posted by john .
name 2 fact families that have only 2 equations
I'm not sure what you are asking.
Since I am not familiar with "fact families," I searched Google under the key words "'fact families' math" to get these possible sources:
(Broken Link Removed)
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.
I hope this helps. Thanks for asking.